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Abstract
Spin-defects in crystal lattices are promising candidates for quantum communication and sensing due to their optical addressability and long spin coherence times. Defect spins in silicon carbide (SiC) boast these properties, with the added advantage of being hosted in a scalable and fabrication-amenable semiconducting platform. Despite these advantages, an outstanding hurdle for SiC-based quantum systems is single-shot readout, a deterministic measurement of the quantum state. In this thesis, I will discuss how we ultimately achieved single-shot readout of single neutral divacancies in SiC via spin-to-charge conversion, whereby the defect’s spin state is mapped onto a long-lived charge state. Using this technique, we report over 80% readout fidelity without pre- or post-selection, resulting in a high signal-to-noise ratio that enables us to measure long spin coherence times. Combined with pulsed dynamical decoupling sequences in an isotopically purified host material, we measure a single-spin coherence time greater than 5 seconds, over two orders of magnitude greater than previously reported in this system. The mapping of these coherent spin states onto single charges unlocks both single-shot readout for scalable quantum nodes and opportunities for electrical readout via integration with semiconductor devices.